I?m struggling with my seat, especially in canter. My instructor says my Seat is fine in walk and trot. However, when I Canter I seem to lose it altogether. I move around a lot in the saddle and in videos it looks like my upper body rocks backwards and forwards. I also find that my lower leg position isn?t secure and I find it hard to give any useful leg aids & keep the horse going forwards. Feeling a bit frustrated with myself. I do have a wonky pelvis which I see an osteopath for & do Pilates. Any helpful advice appreciated.